Fixing up a Drake 2-B - Mod question

[Bill Meara]

With the help of Avery, W3AVE, I was able to fix the dial/drive
problem in my beloved Drake 2-B.   The original owner had many years
ago, successfully fixed the "too fast tuning" problem by putting a
Jackson Brothers 6:1 reduction drive between the tuning knob and the
little shaft mechanism that turns the string inside the 2-B.   My
reduction drive had apparently been damaged (probably during shipping)
by some sort of lateral shock.  This introduced all sorts of
wobbliness and jumpiness in the tuning.  Putting in the new drive
fixed this right up.  Tuning is now smooth as silk.

I'm not using the original Drake knob and skirt.  I know this will be
upsetting to BA purists, but I put a nice big knob from an old
Hammarlund SP-600 on the Drake.  I also used a little shaft extender
so that this knob sits about an inch or so out from the front panel of
the RX.  This allows me to tune without bumping my hand on the side of
the cabinet.

I noticed one other mod that the previous owner put in there:  He ran
a shielded cable from the input (grid) of the first audio amplifier to
a plug on the back of the chassis.   I'm thinking that he was using
this to sample the audio (perhaps for input to a scope?).  Any other
thoughts on what this mod was for?

This morning I fired up the old Drake and its companion HT-37.   On 20
meters using an inverted Vee, I called CQ and the first response was
from Steve, VK6VZ near Perth.  We had a very nice QSO.

73   Bill   N2CQR